Dust separating fan



E. A. LUNDSTROM DUST SEPARATING FAN Filed April 17, 1943 Nov. 28, 1944.

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I INVENTOR.

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Patented Nov. 28, 1944 DUST SEPARATING FAN Ernest A. Lnndstrom, Wellsvllle, N; Y., assignor to The Air Preheater Corporation, New York,

' Application-April 17,1943, Serial No. 483,374

2 Claims. (of. 183-35) The present invention relates to fluid displacing apparatus such as fans or pumps and particularly to improvements in the construction of a pump or fan arranged to have a double 8.0- I

tion effect on the fluid handled such as air, other gas or liquid.

The fluid displacing apparatus of this invention embodies a novel construction and arrangement for the impeller blades together with a novel disposition of the latter with respect to the housing enclosing the impeller so that a single stream of fluid may be twice acted upon by the impeller blades. The invention also contemplates the use of the apparatus as a dust-separator when handling gas or air by providing it with collecting scoops positioned to' catch dust and other particles separated under the action of centrifugal force. e

For convenience of description the apparatus will be referred to in its aspect as a fan and the invention will be best understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

Figure l is a longitudinal sectional view through a centrifugal fan embodying the present.

tially disposed sealing members 22, 23. These, as illustrated, comprise two rings rabbeted on their inner and outer peripheral faces, respectively, and interlockingly engaged. The ring '22 is formed on the inner face of the partition while ring 23'is mounted about the impeller around the outer end edges of the blades l3. Rabbeted annular sealing members 36, 31 on the outer left hand corners of the impeller blades and opposite thereto On the inner face of the left hand end wall seal the chamber I! from inlet I5 to prevent direct flow of fluid therebetween. The right hand corners of theblades are attached to a ring 38. g

The chamber H has a tangentially disposed outlet 24 which is directed horizontally. The right hand end wall 4| is dished inwardly to the outer face of the hub disc beyond the inner edges 'of the blades 13 so that chamber I8 is a hollow torus. As described below the impeller is'provided with two separate groups of passages 30 and 3! with the passages of one group alternating with those of the other. The opening ll in the invention and constructed to also function as a dust separator.

Figure 2 is an end view on a reduced scale of the fan and shows the arrangement of the outlets for the fluid; x

Figure 3 is an end view and Figure 4 a side view of the impeller of the fan illustrated in Figure 1, some parts being broken away.

In the drawings the numeral l0 designates the shaft of a fan impeller driven by a motor ll andprovided with a hub l2. Rectangular, radially projecting blades l3 are attached near their inner comers to hub l2, the blades extending axialleft hand end wall of housing It admits the stream of fluid, such as air, which then flows through the set of passages 30 of the impeller into chamber l8 and back through the other set of impeller passages 3 I; into chamber I! and to outlet 24.

In the form shown herein to create two groups of passages 30, 3|, alternate spaces between adjacent blades are closed at 32 and 33 along one pair of opposite edges while the intermediate spaces are closed at 34, 35 along the other pair of oppositeiedges. Thus the intermediate passages 3| lead from the inlet l5 at the left to the chamber l8 while the alternate passages 3| lead from chamber l8 at the right to chamber I1.

1y of the latter, or inclined somewhat in relation The impeller is completely surrounded by a generally cylindrical housing ll formed in one end wall with an opening l5 for admitting air or gas to the passages between the fan blades. The interior of housing ll hastwo and the edges of the fan blades by circumferen- Inasmuch as the stream of, fluid flows through passages 30 in a general upward and radially outward direction as the impeller rotates a centrifugal action is imposed thereon which becomes effective to throw particles of dust or other minute entrained material toward the inner wall. surface of the end wall 4| of chamber I8, Fig, 3. Due to the abrupt change in direction of the fluids as it rounds the right hand corners of the blades in passing from passages 30 to enter adjacent passages 3|, the centrifugal separating effect is accentuated. Accordingly; a series of annular collector scoops or guide vanes lll are provided as shown in Fig. 3 projecting from the end wall 4| so that the disentrained particles which impinge on the rings are directedto a discharge outlet 42 i atth'e bottom of the fan housing.

each other at the Junction between the partition 'Although in theforegoing description. the invention has been described as embodied .in a fan 2 aseassa and although the term fan is used in the appended claims, it will be appreciated that its principles may be applied to pumps for handling liquid as well as gaseous fluids.

What I claim is: t

1. In a centrifugal fan; an impeller comprising a hub; a plurality of polygonal axially and outwardly extending plates spaced circumferentially about and each abutting said hub adjacent one corner and attached to said hub; a housing surrounding said impeller and formed in one end wall with a fluid inlet at one side of the impeller;

cooperating sealing means mounted on the outer corners of said plates and on the inner wall of said housing for dividing the interior thereof into a fluid inlet chamber at said one side of the impeller and into intermediate and outlet chambers surrounding said impeller; means closing the spaces between certain edges of adjacent plates so arranged as to form two groups of passages through the impeller with passages of one group alternating with those of the other, passages of each group communicating at adjacent ends with said intermediate chamber and the opposite ends of the passages of the two groups being radially spaced and communicating respectively with said inlet chamber and with said outlet chamber; means forming a, fluid discharge outlet leading from said outlet chamber, whereby fluid entering into said inlet chamber passes through one group of impeller passages into said intermediate chamber and flows from the latter through the other group of passages to the outlet chamber; means forming a dust discharge outlet from said intermediate chamber; and annular scoops mounted in said intermediate chamber on the inner surface of the other end wall of said housing and facing said impeller for receiving dust centrifugally separated from air passing from one group of passages into the other and for directing it to said dust outlet.

40 said dust outlet.

2. In a centrifugal fan; an impeller comprising a hub; a plurality of polygonal axially and outwardly extending plates spaced circumferentlally about and each abutting said hub adjacent 5 one corner and attached to said hub; a housing surrounding said impeller and formed in one end wall with a fluid inlet at one side of the impeller; cooperating sealing means mounted on the outer corners of said plates and on the inner wall of said housing for dividing the interior thereof into a fluid inlet chamber at said one side of the impeller and two adjacent annular chambers surrounding said impeller and constituting an outlet chamber and an intermediate ,chamber; mean closing the spaces between certain edges of adjacent plates so arranged as to form two groups of passages through the impeller with passages of one group alternating with those of the other, passages of each group communieating at adjacent ends with said intermediate the lower edges of said plates and thence out- .wardly and axially through the other group of passages to the said outlet chamber; means forming a dust discharge outlet from said intermediate chamber; and annular scoops mounted in said intermediate chamber on the inner surface of the other end wall of said housing and facing said impeller for receiving dust centrifugally separated from air passing from one group of passages into the other and for directing it to ERNEST A. LUNDSTROM. 

